Defogger Relay Test

Rear Window Defogger Relay Test:

1. Stop engine. Connect the negative lead of a 0-15 volt range voltmeter to a known good vehicle electrical ground.
2. Reconnect rear window grid connections disconnected during the Fuse and Electrical Short Test. Start engine and with the system OFF check the voltages present at the rear window defogger relay and rear window defogger grid. Refer to the Rear Window Defogger Relay Test table for diagnosis.